Chylomicron, free fatty acid and ketone body metabolism of isolated liver cells and liver homogenates

Abstract

1. 1. Fortified rat-liver homogenates oxidized a significant quantity of chylomicron lipid. 2. 2. A procedure for isolating and incubating isolated liver cells was devised which supports endogenous respiration for longer periods than previously described. 3. 3. Endogenous free fatty acids accumulated in the incubating liver cell system if bovine serum albumin was present. 4. 4. Isolated liver cells oxidized chylomicron fatty acid esters and converted both free fatty acids and chylomicron triglyceride fatty acids into phospholipids. Ca2+ promoted lipolysis and depressed oxidation of chylomicrons by isolated liver cells. Results suggest the importance of some type of direct uptake of chylomicron fatty acids by the liver. 5. 5. Removal of Kupffer cells from the isolated liver cell preparation did not alter ketogenesis in the system, suggesting that parenchymal cells produce most, if not all, of the ketone bodies generated by the liver.